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package org.apache.juneau.rest.response;

import static org.apache.juneau.internal.StringUtils.*;

import java.io.*;
import java.util.*;

import org.apache.juneau.*;
import org.apache.juneau.http.*;
import org.apache.juneau.rest.*;

/**
 * Response handler for {@link Writable} and {@link ReaderResource} objects.
 * 
 * <p>
 * Uses the {@link Writable#writeTo(Writer)} method to send the contents to the
 * {@link RestResponse#getNegotiatedWriter()} writer.
 * 
 * <h5 class='section'>See Also:</h5>
 * <ul>
 * 	<li class='link'><a class="doclink" href="../../../../../overview-summary.html#juneau-rest-server.MethodReturnTypes">Overview &gt; juneau-rest-server &gt; Method Return Types</a>
 * </ul>
 */
public final class StreamableHandler implements ResponseHandler {

	@Override /* ResponseHandler */
	public boolean handle(RestRequest req, RestResponse res, Object output) throws IOException, RestException {
		if (output instanceof Streamable) {
			if (output instanceof StreamResource) {
				StreamResource r = (StreamResource)output;
				MediaType mediaType = r.getMediaType();
				if (mediaType != null)
					res.setContentType(mediaType.toString());
				for (Map.Entry<String,Object> h : r.getHeaders().entrySet())
					res.setHeader(h.getKey(), asString(h.getValue()));
			}
			try (OutputStream os = res.getOutputStream()) {
				((Streamable)output).streamTo(os);
			}
			return true;
		}
		return false;
	}
}

